TABLE 1.

SELECTED BASELINE CHARACTERISTICS OF CHILDREN'S HEALTH STUDY PARTICIPANTS WITH NO HISTORY OF PHYSICIAN-DIAGNOSED ASTHMA OR LIFETIME HISTORY OF WHEEZING AT STUDY ENTRY (FOURTH AND SEVENTH GRADE)

	N (2,609)	Ratio of Observed and Expected Follow-up Time
Age at entry, yr
8–10	1,731	0.76
11–12	393	0.70
13–15	485	0.76
Race/ethnicity
White	1,388	0.76
Hispanic	798	0.75
Asian	141	0.82
African-American	138	0.67
Mixed	83	0.73
Other/unknown	61	0.70
Sex
Female	1,415	0.76
Male	1,194	0.74
Overweight at entry
No	2,037	0.77
Yes	322	0.73
Parental history of asthma
No	2,120	0.76
Yes	319	0.74
History of allergy
No	2,041	0.76
Yes	469	0.75
History of allergic rhinitis
No	2,127	0.76
Yes	429	0.74
Humidifier use
No	1,875	0.76
Yes	612	0.74
Maternal smoking during pregnancy
No	2,165	0.77
Yes	362	0.70
Current maternal smoking at entry
No	2,318	0.76
Yes	244	0.68
Household SHS exposure at entry
No	2,100	0.76
Yes	457	0.72
Pests in home*
No	530	0.73
Yes	1843	0.76
Dogs in home
No	1,153	0.75
Yes	1,456	0.76
Pets in home†
No	617	0.74
Yes	1,992	0.76
Health insurance
No	459	0.74
Yes	2,101	0.76
Parental Income‡
⩽ $14,999	362	0.68
$15,000–49,999	938	0.74
> $50,000	872	0.78
Parental Education‡
Less than high school	383	0.72
At least high school	503	0.76
Some college	1,025	0.75
College and above	587	0.77

^*Presence of any pests (rats, mice, cockroaches, ant, spiders, termites and others) in the home within 12-mo period before study entry.

^†Presence of any pets (dogs, cats, hamster, birds, and others) in the home within last 12-mo period before study entry.

^‡Subtotals are not equal to 2,609 due to missing data for subjects.